Motorized vehicles include a power plant (e.g. engine or electric motor) that produces driving power. The driving power is transferred through a transmission to a driveline for driving a set of wheels at selected gear ratios. As is well known, automatic transmissions shift automatically to the appropriate gear ratio based on various vehicle operating conditions including speed and torque. Typically, a desired transmission operating mode or range is selected by the vehicle operator. The ranges provided by most automatic transmissions generally include Park, Neutral, Reverse and Drive. In Drive, the automatic transmission automatically shifts between three, four, five or even six different forward gear ratios based on the vehicle operating conditions.
Traditionally, a driver interface device is provided which the vehicle operator shifts to select the desired transmission range. The driver interface device is linked to the automatic transmission by a range shift mechanism which typically includes a series of interconnected mechanical devices such as levers, push/pull rods, cables and the like.
More recently, electronic transmission range selection (ETRS) or “shift-by-wire” range shift systems have been developed. Typically, a shift-by-wire range shift mechanism is based on detection of an external input through a driver interface device. Switches associated with the driver interface device send a mode signal to a transmission control module that is indicative of the selected transmission range. Thereafter, the control module actuates electric motors, solenoids and/or hydraulics to operate the transmission in a manner corresponding to the range select position.